Type 2 Diabetes and Thyroid Health

Published November 17 2014

Millions of people have type 2 diabetes. And while genetics does seem to play a role in the development of this condition, lifestyle and environmental factors have a greater impact. As a result, type 2 diabetes is usually preventable. For those who currently have type 2 diabetes, it is possible to reverse this condition, although for many people it can be challenging. There is also a relationship between type 2 diabetes and thyroid health, as many people with type 2 diabetes also have a thyroid condition.

In past articles I’ve discussed the condition insulin resistance, and type 2 diabetes is not only characterized by insulin resistance, but also by hyperglycemia. Insulin secretion can be impaired as well. Most people with type 2 diabetes have other conditions such as high blood pressure, elevated lipid markers (high total cholesterol, triglycerides, and LDL), along with low HDL levels. These factors increase the person’s risk of developing cardiovascular disease.

What is Metabolic Syndrome?

Many people reading this have heard of the condition known as metabolic syndrome. But what is the difference between type 2 diabetes and metabolic syndrome? Metabolic syndrome is defined as a group of risk factors which increases the risk for developing conditions such as heart disease, stroke, and diabetes (1). I’ve already mentioned most of these risk factors, as they include high blood pressure, high triglycerides, high LDL/low HDL levels, a large waistline, and a high fasting blood sugar. Most people who are obese and/or have type 2 diabetes will be classified as having metabolic syndrome.

How is Type 2 Diabetes Diagnosed?

Type 2 diabetes is usually diagnosed through blood tests. Three of the most common tests are the hemoglobin A1C, fasting plasma glucose, and an oral glucose tolerance test. Although many medical doctors routinely recommend a fasting glucose to their patients, the hemoglobin A1C is more accurate, as it is a measurement of the patient’s blood glucose levels over a 3-month period. Another advantage of this test is that it doesn’t involve fasting. Typically someone is classified as being prediabetic if their Hemoglobin A1C is between 5.7 to 6.4 percent, and if the person’s results are 6.5 percent or greater then this means the person has diabetes. Of course no test is perfect, and so if someone tests for hemoglobin A1C and the results are 6.5 percent or higher I probably would recommend running another test. Also keep in mind that false results can occur if someone has a condition which affects their hemoglobin, such as anemia.

The oral glucose tolerance test is also an option for diagnosing diabetes. Although it is more sensitive than a fasting glucose, it’s even less convenient, as not only does it involve fasting for at least 2 hours, but then the person will need to drink a liquid which consists of 75 grams of glucose. This frequently is confirmed by a second test.

More About The Causes Of Type 2 Diabetes

I’d like to discuss in greater detail why people develop type 2 diabetes. There is no question that dietary and lifestyle factors are responsible for most cases of type 2 diabetes. Diet and exercise obviously both play a big role, as if someone doesn’t exercise regularly and eats a high carbohydrate diet consisting mostly of refined foods and sugars then this will increase the chances of the person developing blood sugar imbalances, insulin resistance, and eventually can lead to type 2 diabetes.

But why then can some people eat poorly for many years and never exercise, yet not develop type 2 diabetes? This is where genetics and biochemical individuality come into play. Without question it isn’t all about diet and exercise. However, it’s very rare for someone who has been eating a healthy diet and exercising regularly for many years to develop diabetes. Part of the problem is that many people don’t know the difference between healthy and unhealthy foods. For example, while most people reading this understand that pasta isn’t considered to be healthy, many others don’t realize this. As a result, someone might eat large servings of pasta three or four days per week, along with some other “healthier” carbohydrates, not realizing that this is causing or contributing to their condition. Keep in mind that I’m not saying that eating pasta or other carbohydrates is what’s causing these problems, but it’s the EXCESS consumption of these foods which are the issue.

Insulin Resistance, Inflammation, and Beta-cell Dysfunction

The development of type 2 diabetes involves two processes (2). Insulin resistance is one factor, which I have discussed in a separate article entitled “Insulin Resistance and Thyroid Health“. Insulin resistance is when the body is no longer responsive to the effects of insulin. Beta-cell dysfunction is another characteristic of type 2 diabetes, as not only is the body not responsive to the effects of insulin, but the amount of insulin produced is insufficient. Once again, insulin resistance and beta-cell dysfunction are usually the result of poor diet and lifestyle choices.

Type 2 diabetes also has an inflammatory component which needs to be addressed. In fact, numerous studies show a relationship between proinflammatory cytokines and type 2 diabetes (3)(4)(5). I’ve discussed cytokines in a post entitled “The Role of Cytokines In Autoimmune Thyroid Conditions“, as these are also present in autoimmune conditions. So whether someone has an autoimmune thyroid condition, type 2 diabetes, or both conditions, they will need to do things to decrease inflammation. However, doing this can be a challenge, and this is frequently why just cleaning up one’s diet and exercising regularly won’t always restore one’s health. I’ll talk more about how to address the inflammation shortly.

The Relationship Between Type 2 Diabetes and Thyroid Conditions

Numerous studies show a correlation between type 2 diabetes and thyroid conditions. The author of one journal article mentioned that the most likely mechanism for the development of type 2 diabetes in those with thyroid conditions is a combination of genetic factors which lead to impaired glucose utilization and overproduction of glucose by the liver, which lead to insulin resistance, and eventually diabetes (6). The same author mentions that both hyperthyroidism and hypothyroidism are associated with insulin resistance. Another study showed that the prevalence of primary hypothyroidism was 11.8% in people with type 2 diabetes (7). The same study mentioned that the use of Metformin therapy in people with type 2 diabetes is associated with a significantly lower prevalence of diagnosed hypothyroidism. So it appears that having type 2 diabetes will increase one’s susceptibility of developing a thyroid condition, and the reverse seems to be true as well.

Is there a relationship between hyperthyroidism and type 2 diabetes? Well, one study assessed the prevalence of newly diagnosed subclinical hyperthyroidism in a cohort of patients with type 2 diabetes (8). Subclinical hyperthyroidism was present in 4.3% of female and 3.5% of male diabetic patients, and so the study concluded that the risk for subclinical hyperthyroidism is increased in women with type 2 diabetes.

Can Type 2 Diabetes Be Cured?

The primary goal of conventional treatment methods is to lower the elevated blood glucose levels associated with type 2 diabetes. Although many medical doctors encourage their patients to eat well and exercise regularly, most will prioritize the medication over restoring health. Although medication might be necessary to take on a temporary basis in some cases, many medical doctors don’t make their patients aware of the potential risks associated with these drugs.

For example, one of the most common drugs recommended for prediabetes and type 2 diabetes is Metformin. Metformin lowers blood sugar levels, but numerous studies show a higher prevalence of vitamin B12 deficiency in those people who take this drug (9)(10)(11). One common symptom of vitamin B12 deficiency is peripheral neuropathy, and this is often diagnosed as diabetic neuropathy (12). As a result, anyone who is taking Metformin should have their vitamin B12 levels monitored on a regular basis. However, it’s important to remember that if you get serum B12 tested you can’t rely on the lab reference range. In other words, you can be well within the lab reference range yet still have a vitamin B12 deficiency.

There are other conventional treatment methods, but the problem is that none of these methods address the cause of the problem. If someone with type 2 diabetes is looking to restore their health back to normal, the following factors need to be addressed:

1. Eat whole foods while limiting the consumption of carbohydrates. Those with type 2 diabetes should eat whole foods, avoid the refined foods and sugars, and limit their carbohydrate intake. In many cases I would recommend to try to eat less 100 grams or less of carbohydrates per day, although this does depend on the person. If someone has severe sweet and carbohydrate cravings then they might need to supplement with the herb gymnema and/or chromium to help control these cravings. Eventually they should be able to control these cravings without taking nutritional supplements.

2. Regular exercise is important. Engaging in 30 to 45 minutes of aerobic exercise three to five days per week is important. Doing some light weight lifting can also be beneficial. However, this might not be enough, as if you are sedentary most of the time then you can’t expect a few weekly aerobic exercise sessions to make a big difference. If your job involves mostly sitting then you need to find a way to become more active. For example, perhaps you can ride a bike to and from work, and then take a walk during your lunch break. Or if you work from home then perhaps you can invest in a treadmill desk and do some or all of your work while walking slowly on the treadmill. Some high intensity interval training can also be beneficial. Of course if you aren’t already following an exercise routine then it probably would be wise to work with a physical trainer, even if it’s only for a few sessions initially.

I realize that some people with type 2 diabetes won’t have the energy to exercise regularly. If this is the case then perhaps you can still do some light walking and light weightlifting a few times per week. Although regular exercise is important, if your energy levels are very low then you might need to focus on these other factors until you have the energy to exercise. And of course if you are experiencing low energy levels due to conditions such as anemia or weak adrenals then these factors need to be addressed.

3. Insulin sensitivity must be improved. Those with type 2 diabetes will need to do things to help improve insulin sensitivity. The first step to accomplish this is by making the dietary changes I mentioned earlier. However, initially it might be necessary to take a few nutritional supplements to help with this. I mentioned gymnema and chromium earlier, and these both can help with insulin sensitivity (13)(14)(15) (16). Alpha lipoic acid can also greatly help (17).

4. The inflammatory process needs to be addressed. This probably is the biggest factor to overcome in those with type 2 diabetes. In fact, stopping the inflammatory process is the biggest factor with most chronic health conditions. I’ve spoken about this in greater detail in past articles and blog posts, including the post I wrote on cytokines. In that post I spoke about the importance of downregulating NF-kappaB by using nutrients such as vitamin D, fish oils, turmeric, and resveratrol. Another important factor for controlling inflammation is improving the health of the mitochondria. Free radicals can damage mitochondria, and if the mitochondria are impaired, this leads to a further increase in free radicals, which contributes to the inflammatory process (18)(19). In fact, numerous studies show a relationship between mitochondrial dysfunction and type 2 diabetes (20)(21).

In summary, type 2 diabetes and thyroid conditions are similar in that genetics, lifestyle, and environmental factors play a role in the development of these conditions. Many people with type 2 diabetes also have thyroid conditions. While the primary goal of most endocrinologists is to use medication to lower blood sugar levels in type 2 diabetics, this condition can usually be reversed. Although eating well and exercising regularly are important factors, it is also necessary to do things to improve insulin sensitivity and control inflammation.